scholarly journals Analytical study on lateral torsional buckling of partially encased beams under ISO834 fire exposure

Fire Research ◽  
2016 ◽  
Author(s):  
Ana Belén Ramos-Gavilán ◽  
Paulo Piloto ◽  
Luís Mesquita
Keyword(s):  
Fire Resistance ◽  
Experimental Tests ◽  
Reduction Factor ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Standard Fire ◽  
Resistance Moment ◽  
The Moment ◽  
In Fire ◽  
Simplified Calculation

European standard EN1994-1-2:2005 provides tabulated values and simplified calculation models for assessing fire resistance of composite beams, but does not consider the design checks against lateral torsional buckling under fire. This research presents an analytical method to calculate the buckling resistance moment of laterally unrestrained partially encased beams in fire conditions. The proposal applies a reduction factor for lateral torsional buckling in fire design condition to the moment resistance of the homogenised section at time t, determined by EN1994-1-2:2005. Two finite element models capable to simulate the thermal and mechanical behaviour of partially encased beams are also presented, including the validation against fire tests conducted by Piloto et al. Based on these models, a numerical analysis of partially encased beams with the same geometry and material properties as used in experimental tests is presented, evaluating different load levels when exposed to standard fire ISO834:1999. The numerical results of fire resistance according to standard EN1363- 1:2012 and the numerical ultimate time, when beams suffer instability, are used to validate the proposal, using experimental and analytical heating result according to EN1994-1-2:2005.

scholarly journals Lateral torsional buckling capacity of corroded steel beams: A parametric study

2021 ◽  
Vol 1201 (1) ◽  
pp. 012038
Author(s):  
G Kullashi ◽  
S C Siriwardane ◽  
M A Atteya
Keyword(s):  
Cross Sections ◽  
Parametric Study ◽  
Analytical Framework ◽  
Reduction Factor ◽  
Steel Beams ◽  
Uniform Corrosion ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Moment Capacity ◽  
The Moment

Abstract Thickness reduction due to uniform corrosion increases the tendency of lateral torsional buckling (LTB) of open cross-sections and it reduces the moment capacity of the beam. The effect of the various corrosion cases on the LTB moment capacity (M b,rd) of the I-beams are investigated in this paper. An analytical framework for patch corroded I-beams is introduced to provide a guideline for simulating the nonlinear lateral torsional buckling behaviour of patch corroded simple beams. Hence the effect of different corrosion scenarios to reduce the buckling reduction factor (η LT) is investigated by conducting a parametric study. Twelve different beam lengths were considered to obtain different non-dimensional slenderness ratios (λ LT) in this parametric study. The degraded buckling curves were obtained for each corrosion scenarios.

Drywall Thermal Properties Exposed to High Temperatures and Fire Condition

2013 ◽  
Vol 62 (1) ◽  
Author(s):  
Md Azree Othuman Mydin
Keyword(s):  
Thermal Properties ◽  
High Temperatures ◽  
Fire Resistance ◽  
Residential Buildings ◽  
Cost Effective ◽  
Standard Fire ◽  
Performance Requirements ◽  
Cost Effective Technique ◽  
Fire Barrier ◽  
In Fire

Drywall is a widespread fire barrier used in house and general building construction. Drywall partitions and ceiling membranes are possibly the most common fire resistant construction approach employed in an extensive range of building types. The utilization of drywall board as prime fire protection of light-flame wood or steel construction is ubiquitous. Drywall board based systems are among those now broadly used, as walls or ceilings and it is principally employed as lining material in light-weight construction, which is a competent and cost effective technique of providing flexible partitioning assemblies in commercial and residential buildings. The thickness of the drywall board lining and the configuration of the framing can be flexibly changed to meet specified fire performance requirements. The use of such systems is increasing every day and there demands to be more research on their properties and behaviour. This paper will presents the properties of drywall board which will includes the assemblies and standard fire tests and the thermal properties of drywall in general and includes suggested properties of drywall by different researchers. Drywall boards shrink and crack at high temperatures, and this leads to collapse of parts of the drywall boards in fire. Fall-off of gypsum in fire affects the fire resistance of the assembly considerably, and cannot be overlooked when evaluating the fire resistance of drywall assemblies

scholarly journals A comparative study of beam design curves against lateral torsional buckling using AISC, EC and SP

2019 ◽  
Vol 15 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Vera V Galishnikova ◽  
Tesfaldet H Gebre
Keyword(s):  
Steel Structures ◽  
Reduction Factor ◽  
Steel Beams ◽  
Steel Beam ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Vertical Loading ◽  
Beam Design ◽  
Overall Stability

Introduction. Structural stability is an essential part of design process for steel structures and checking the overall stability is very important for the determination of the optimum steel beams section. Lateral torsional buckling (LTB) normally associated with beams subject to vertical loading, buckling out of the plane of the applied loads and it is a primary consideration in the design of steel structures, consequently it may reduce the load currying capacity. Methods. There are several national codes to verify the steel beam against LTB. All specifications have different approach for the treatment of LTB and this paper is concentrated on three different methods: America Institute of Steel Construction (AISC), Eurocode (EC) and Russian Code (SP). The attention is focused to the methods of developing LTB curves and their characteristics. Results. AISC specification identifies three regimes of buckling depending on the unbraced length of the member ( Lb ). However, EC and SP utilize a reduction factor (χ LT ) to treat lateral torsional buckling problem. In general, flexural capacities according to AISC are higher than those of EC and SP for non-compact sections.

Reduction in the Critical Moment for Lateral Torsional Buckling of Coped Beams

2015 ◽  
Vol 797 ◽  
pp. 3-10 ◽  
Author(s):  
Karolina Brzezińska ◽  
Roman Bijak
Keyword(s):  
Computational Analysis ◽  
Reduction Factor ◽  
Bottom Flange ◽  
The Finite Element Method ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
End Plate ◽  
Analytical Formulas ◽  
Beam Section ◽  
Plate Connection

The paper presents a computational analysis of the effect constructional details of coped connections, assumed to be a fork support in calculations, on the critical LTB moment values. On the basis of analytical formulas by Lindner [1], a formula, having a simple form, was derived for the reduction factor rn for the critical LTB moment. The parameters for the formula were presented in a tabular form, taking into account the beam section (IPE/HEA), the type of beam to end-plate connection (Types 1-3), the load type (q / P) and the way the load is applied (top / bottom flange). The correctness of the derived formula was validated on the basis of the analytical results and the Finite Element Method results obtained with the Abaqus/CAE software. In the program, the beam geometric dimensions and connections were represented as volumetric finite elements. Additionally, the dimensions of the end-plate for IPE and HEA section series were arranged in a systematic manner following the British catalogue.

scholarly journals FIRE RESPONSES AND RESISTANCE OF CONCRETE-FILLED STEEL TUBULAR FRAME STRUCTURES

2010 ◽  
Vol 10 (02) ◽  
pp. 253-271 ◽  
Author(s):  
MIN YU ◽  
XIAOXIONG ZHA ◽  
JIANQIAO YE ◽  
YI Li
Keyword(s):  
Finite Element ◽  
Fire Resistance ◽  
Load Capacity ◽  
Element Model ◽  
Dynamic Responses ◽  
Frame Structures ◽  
Steel Beams ◽  
Standard Fire ◽  
Cfst Columns ◽  
In Fire

This paper presents the results of dynamic responses and fire resistance of concrete-filled steel tubular (CFST) frame structures in fire conditions by using the nonlinear finite element method. Both strength and stability criteria are considered in the collapse analysis. The frame structures are constructed with circular CFST columns and steel beams of I-sections. In order to validate the finite element solutions, the numerical results are compared with those from a fire resistance test on CFST columns. The finite element model is then adopted to simulate the behavior of frame structures in fire. The structural responses of the frames, including the critical temperature and fire-resisting limit time, are obtained for the ISO-834 standard fire. Parametric studies are carried out to show their influence on the load capacity of the frame structures in fire. Suggestions and recommendations are presented for possible adoption in future construction and design of similar structures.

Behaviour of corrugated web girders subjected to lateral-torsional buckling: Experimental tests and numerical modelling

Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 152-168
Author(s):  
A.A. Elkawas ◽  
M.F. Hassanein ◽  
A.M. El Hadidy ◽  
M.H. El-Boghdadi ◽  
Mohamed Elchalakani
Keyword(s):  
Numerical Modelling ◽  
Experimental Tests ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Corrugated Web

scholarly journals Elastomer Spacers in Fire Conditions

2017 ◽  
Vol 26 (3) ◽  
pp. 109-119
Author(s):  
Paweł Roszkowski ◽  
Bartłomiej Sędłak ◽  
Paweł Sulik
Keyword(s):  
Thermal Degradation ◽  
Fire Resistance ◽  
Load Capacity ◽  
Combustible Material ◽  
Cavity Depth ◽  
Standard Fire ◽  
Degradation Rates ◽  
In Fire ◽  
Resistance Performance ◽  
Fire Conditions

Abstract In the paper, fire resistance of linear joints seal made of elastomer spacers under standard fire conditions, and thermal degradation range of EPDM elastomeric spacers are investigated. The geometry of elastomer spacer joints is important not only for their load capacity under normal conditions - thickness, width, and cavity depth can also influence fire resistance performance. Linear joints of different thicknesses and widths have been tested. The fire insulation and fire integrity were verified for various arrangements. Relatively low thermal degradation rates have been measured, given that EPDM is a combustible material.

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